Equation 8 · Part 6 · The Valley of Stability Is a Fitness Landscape
Symbol A^2/3
What this part means
/3 is one of the signed contributions combined to compute the quantity on the left.
Its job in the formula
/3 is one of the signed contributions combined to compute the quantity on the left.
Full expression→Symbol A^2/3→Article meaning
The passage around this formula
The quantity that plays fitness’s role has a name in nuclear physics already: binding energy per nucleon, B(A,Z)/A , where A = N + Z is the mass number. It is the energy that would have to be supplied to disassemble a nucleus into Z free protons and N free neutrons, divided by the number of nucleons, and a higher value means a more tightly bound, lower-energy configuration — precisely the sense in which a fitness function assigns a scalar payoff to a state. The theoretical account of how that payoff varies across the chart is the semi-empirical mass formula, first written down by Carl Friedrich von Weizsäcker in 1935 as a liquid-drop model of the nucleus [ 11 ] . In one common form, the…
Learn the underlying idea
An exponent tells how a base is used in multiplication. In x³, x is the base and 3 is the exponent: x³ = x × x × x.
Open the illustrated exponents: repeated multiplication and powers guide →
See this notation across published equations →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.